Sight-adjustment.



No. 837,835. PATENTBD DEC. 4, 1906` J. w. HIoKs al H. nl GHAPMAN. SIGHT ADJUSTMENT.

LPILIUATIOI FILED IY 81, 1905.

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SIGHT ADJUSTMENT.

APPLICATION FILED KAYSI. 1905.

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UNITED STATES PATENT OFFICE.

JAMES W. HICKS AND HOWARD D. CHAPMAN, OF WASHINGTON, DISTRICT OF COLUMBIA.

SIGHT-ADJUSTMENT.

Specification of Letters Patent.

Yatented Dec. 4, 1906.

To all whom, it may concern:

Be it known that we, J AMES W. HICKS and lloWAninD. CHAPMAN, citizens of the United States, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in Sight-Adjustments; and We do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to sight-adjusting mechanism wherein the sight at the breech of a gun is raised and lowered by manipulationof a hand-Wheel.

As ordinarily constructed the sight is carried at the up er end of arack-bar that -operates in a siiita le guide at the breech of a gun and is movable vertically throu h the medium of a pinion carried by a sha on which the hand-wheel is mounted. It is found in practice that the recoil of the gun causes the sight to settie, so that readg'ustment of the sight is required from time to time, even when firing at the same target.

The object of the present invention is to rovide a oonstructionwherein the adjustingsh aft that carries the pinion will be held normally against rotation by action of a clutch having certain of its members carried by the shaft and adapted to coperate with a xed member carried by the gun, the hand-wheel having a degree of lost motion on the shaft, so that pins carried thereby may first engage and release certain members of the clutch and subse uently shift the shaft in a correspending direction. Thus the rack will be held by the pinion against settling or movement in either direction, excepti under the direct infiuence of the hand-Whee In the drawings forming a portion of this specification, and in which like numerals of reference indicate similar parts in the several views, Figure 1 is a view showing the ad justing-rack, its guide, and the adjustingpinion in rear elevation and the hand-wheel with the clutch mechanism for holding the adjusting-shaft at times stationary, artiy in section and artly in elevation. ig. 2 is a section on line 2 2 of Fig. 1 looking in the direction of the hand-Wheel, the We of the clutch-drum bein partly broken away to permit of better il ustration of tljieparts beyond them. Fig. 3 is a section on line 3 3 of Fig. 1. Fig. 4 is a detail perspective view of "the releasing-rocker. Fig. 5 is a detail perspective view of one of the clutch-dogs.

Referring now to the drawings, there is shown at l() the guide-block such asis carried by the breech of n gun and in which is mounted a vertically-novablc rack-har 11, carrying at its upper end any ty ie of sight 12. At one side of the idebloc 10 is a rearward extension 13, aving a threaded opening 14, in which is screwed one end of a sleeve 15, upon the opposite end of which is formed a web 16, that supports e chitehdrum 17, the sleeve termine, in fact, an elongated hub for the chitc i-driim. The web 16 is at one edge of the clutch-drum and the major portion of the drum rejects beyond the end face of the hub at tliat end carrying the web.

Mounted in the sleeve or hub 15 is a shaft 18, at one end of which is fixed a pinion 19', that meshes with the rack-bar l1, so that when the shaft is rotated in one direction or the other the rack-bar, and therewith the sightgvill be correspondingly shifted vertica ly. The shaft 18 extends through and beyond the clutch-drum 17 and is provided with' spaced radiating flanges 19 and 20, between whioh are ivoted the inner ends of two pairs of clutc -dogs The dogs of one pair are shown at 21 and 22 and the dogs of the other air are shown at 23 and 24. That ortion o the dog which lies between the anges 19 and 2() is of less width than the remaindermf the dog, thus forming shoulders 24', which overlie the edges oi said flanges,

and the said flanges are shouldered, as at 24, to limit the movement of the dogs against the tension of the springs 25 and 28, it being understood, however, that the dogs normally lie in slightly-spaced relation to the said shoulders 24, one abutting the saine when mi ved out of engagement with the clutchdrum, in a manner to be hereinafter described. Each dog is so pivoted and proportioned that a line drawn from the axis of its ivot to its distant point is greater than a ine drawn from its axis to the inner face of the clutch-drum radially of the drum. In consequence, as each dog is moved pivotally in one direction it inipinges against the inner ffice of the druni, and when moved in the opposite direction it releases the drum. The pair of dogs 21 and 22 engage the clutch-drum when moved pivotally in one direction rotatably of the drum or around the drum, while the dogs 23 and 24 engage the drum when moved pivotally in the the opposite direction around the drum. lt will be noted that the dogs of one cooperating pair alternate with thoseof theothercooperating pair,or, inother words, the dogs of each pair are diametrically opposite. Aspring-plate 25 is sprung into position between the dogs 21 and 24, with its ends engaged beneath the lugs 26 and 27, respectively, on the mutually adjacent faces of t e dogs, the springs serving to hold the dogs yieldably in contact with the inner face of the clutch-drum. Similarly, a spring-plate 28 is sprung into position between the dogs 22 and 23, with its ends` beneath lugs 28 and 29 on the mutually adjacent faces of the dogs, and serves to hold them -yieldably against the inner face of the clutch-drum.

With the construction thus far described it will be seen that if it be attempted to rotate the shaft 1S in one direction the dogs 21 and 22 will engage the clutch-drum to prevent such rotation, while the dogs 23 and 24 will engage the clutch-drum to prevent rotation in the opposite direction.

Between the pair of dogs 21 and 23 is disposed a T-shaped rocker 3U, the stem of which is dis )osed between the flanges 19 and 2() and hel in such position by means of a pin 31, passed through the flanges and through the slot 32, formed through the stem of the rocker and extending longitudinally thereof. The ends of the rocker are rounded as illustrated and rest against the slanting adjacent faces of the dogs 21 and 23, so that when the rocker is shifted in one direction it swings the dog 21 from engagement with the clutch-drum and when shifted in the opposite direction it swings the dog 23 from engagement with the clutch-drum. A second rocker 34 of T shape has its stein disposed between the flanges 19 and 20, diametrically opposite to the rocker 30, in which position 1t 1s held pivotally and slidably by a pin 35,

assed through the flanges and through the ongitudinal slot 36 in the stem of the rocker. The ends of the head of the rocker 34 are disposed against the slanting adjacent faces of the dogs 22 and 24, so that when the rocker is shifted in one direction the dog 22 is moved from engagement with the clutch-drum, and when shifted in the oppositedirection the dog 24 is shifted from engagement with the clutch drum To release the proper dogs and subsequently rotate the shaft 1S in the corresponding direction to raise or lower the sight, a hand-wheel 37 is provided and is rotatably mounted upon the outer end of the shaft, in which position it is held by a retaining-screw 38, the head of which lies in a countersink in the end of the hub of the wheel, as illustrated. Through the web 39 of the handwheel are engaged two pins 41 and 42, which lie, respectively, between the rockers 30 and 34 and the inner face of the clutch-drums. The rim of the hand-wheel extends rearwardly, as shown at`43, to entirely inelose or cover the outer face of the clutch-drum.

To lower the rack-bar 11 and therewith the sight 12, the hand-wheel is grasped and moved to the right, at which time the pins 41 and 42 are correspondingly shifted, so that the pin 41 passes to the left, in Fig. 2, and pin 42 passes to the right, so that the rockers are correspondingl shifted or swung to press the dogs 23 an 24, respectively, from engagement with the clutch-drum, alter which continued movement of the handwheel serves to rotate the shaft 18 by reason have moved to their limit continued movement of the hand-wheel serves to rotate the shaft 1S, and therewith the pinion 19, to raise the rack-bar and therewith the si ht.

It will be of course understoo that when the hand-wheel is shifted in either direction the pair of dogs that are not released by action of the pins 41 and 42 drag over the Inner face of the clutch-drum. It Will of course be understood that the hand-Wheel may be of any desired size and that any suitable materials and proportions may be used for the various parts, and, furthermore, that the invention may be embodied in a mechanism for raising and lowering under an specific conditions and in connection witli any specific apparatus to which it is applicable.

lVlnlt is claimed is- 1. In an apparatus of the class described, the combination with an adjusting-shaft having a flange formed thereon, of a fixed clutch-drum, clutch-dogs pivoted to the flangr` and arranged for engagement with the drum to hold the shaft against rotation in either direction respectively, rocker elements carried by the ange and arranged to en age certain of said clutch-dogs, a hand-w leel carried by the shaft, and means carried by the hand-wheel and arranged for engagement with the said rocker elements when the hand-wheel is moved in either direction and to subsequently rotate the shaft in a correspending direction.

2. In an apparatus of the class described,

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the combination with an adjustable shaft having a flange formed thereon, a fixed clutch-drum, clutch-dogs pivoted to the flange and arranged for engagement with the dru'm to hold the shaft against rotation in either direction respectiveiy, and a handwheel carried b the shaft, means carried by the Han fe and l'bcated between pairs of said clutche dogs for actuation by said hand- Wheel to engage the dogs and rotate the shaft in a corresponding direction.

3. In an apparatus of the class described, the combinationwith an adjusting-shaft, of a fixed clutch member, clutch members carried by the shaft and adapted to engage the.

fixed member and hold the shaft against rotation in either direction respective] a rocker carried by the shaft and movablb to shift either shaft-clutch member from engagement with the fixed clutch member when rocked in the correspondin direction, a hand-Wheel movable upon the s aft, and a pin carried by the hand-Wheel and movable therewith to engage and shift the rocker in the eorrespondin direction when the handwheel is oscillate the rocker bein ada ted to lie in the path of the pin when eit er s iaftclutch is disengaged, whereby the shai t will be rotated by continued movement of the hand- Wheel.

4. In an apparatus of the class described, the combination with an adjusting-shaft, of a fixed clutch-drum encircling the shaft, pairs of clutch-dogs pivotally connected with the shaft and movable into and ont of engagement with the clutch-drum. said pairs of dogs being adapted to hold the shaft against rotation in opposite directions when engaged with the clutch-drum, means for holding the dogs yieldably in engaging positions, a rocker pivotally connected with the shaft between each pair of oppositelyoperable dogs and adapted to disengage them alternately when rocked, a hand-Wheel movable upon the shaft, and pins carried by the hand-Wheel and disposed to engage and shift the rockers to dsengage either oflike dogs and subsequently rotate the shaft when the handwheel is moved in either direction.

In testimony whereof We afiix our signatures in presence of two Witnesses.

JAMES W. HICKS. HOWARD D. CHAPMAN. Witnesses:

JAS. M. BROOKS, lfVlLLlAM L. HARVEY. 

